Aliphatic diols, diacids and their derivatives [diamines, diisocyanates, etc.] with sizable molecular weights are technologically important and presently commercially unavailable monomers.
Phillip S. Bailey in Chemical Reviews, Vol. 58, page 925 [1958] describes a review of the reactions of organic compounds with ozone. On page 957 he discloses an order of decreasing ease of ozonolysis for simple and substituted systems qualitatively as follows: simple alkenes: easier than anthracene: easier than phenanthrene: easier than naphthalene: easier than benzene.
E. B. Jones et al. in Journal of Polymer Science Part A, Vol. 2, page 5313 [1964] discloses that butyl rubber dissolved in methyl cyclohexane is ozonized and reduced to produce polyisobutylene glycol.
Thomas W. Boyer in U.S. Pat. No. 3,346,631 discloses the preparation of a liquid carboxylated polymer by dissolving a solid or liquid polymer, derived from the polymerization of a conjugated diene monomer or mixture of such monomers with other monomers copolymerizable therewith, in a solvent of a type which is suitable as a medium for carrying out ozonization reactions, contacting the resulting solution with ozone and processing the ozonized polymer, for example, with steam to form the carboxylated polymer. Suitable solvents disclosed are carbon tetrachloride, paraffinic solvents such as pentane, hexane and heptane, aromatic solvents such as benzene and toluene.
Albert F. Preuss in U.S. Pat. No. 3,417,020 discloses the preparation of oil-soluble saturated aliphatic polymers by contacting a polyolefin or mixtures of polyolefins in liquid state with ozone. Since the polyolefins tend to be viscous, it is desirable according to Preuss to extend them with one or more solvents which are inert to ozone under the conditions of the reaction, such as hexane, heptane/methanol, toluene/methanol, hexane/methanol or octanol/decanol.
G. W. Burton in U.S. Pat. No. 3,514,432 discloses the preparation of carboxy terminated polyiso olefins by ozonization of a particular type of butyl rubber dissolved in a solvent including aliphatic hydrocarbons, such as pentane, hexane, heptane or the like or their chlorinated derivatives in the presence of a pyridine.
John E. Manton et al. in Canadian Pat. No. 792,805 issued Aug. 20, 1968 disclose that substantially saturated alpha-omega dihydroxy liquid polymers may be prepared by ozonizing a solid copolymer comprising 90 to 95 mol percent of an acyclic C.sub.2-8 mono olefinic hydrocarbon copolymerized with 10 to 0.5 mol percent of an acyclic C.sub.4-12 diolefinic hydrocarbon and dissolved in a suitable inert solvent such as pentane, hexane, cyclohexane, or carbon tetrachloride. The ozonization proceeds until substantially all of the olefinic bonds in the backbone chains of the copolymer molecules have been converted into ozonide structures and the ozonide structures are then cleaved by a reducing agent to form the liquid polymer.
Polymer Corporation Limited discloses in Belgium Pat. No. 773,052 the preparation of new polymers with reactive terminal groups by dissolving a high molecular weight polymer containing at least 5 mol percent of carbon-carbon double bonds, preferably in an aliphatic or saturated cycloaliphatic or a halogenated hydrocarbon, and then ozonizing the polymer. It is further disclosed that the treatment of ethylene-butadiene copolymers with ozone in an inert solvent, such as tetrachloroethane leads to products which after polyesterification or polyamidation are highly cross-linked and deeply discolored.
Liquid carboxyl-terminated polymers have been disclosed by J. M. Meyer in U.S. Pat. No. 3,910,990. They are obtained by dissolving copolymers of ethylene with 1-olefins having up to 20 carbon atoms in an ozone resistant solvent and contacting the resulting solution with ozone.
Greene et al. in U.S. Pat. No. 3,857,826 disclose preparation of fluid, hydroxyl-terminated ethylene/propylene copolymers by ozonolysis of a random ethylene/propylene/butadiene terpolymer at temperatures below 0.degree. C. in a solvent containing up to 5 weight percent of ethanol or a higher alcohol.
Ionizable acids can be introduced into polymers conventionally by either (1) chain termination during the polymerization, by the introduction of acid bearing or acid forming self terminating monomers; (2) copolymerization with acid bearing monomers to obtain various amounts and distributions of acid groups pendent from the main chain; and (3) by a random reaction of an ionizable species with a side group along the chain for yielding random distribution of ionizable end groups. Examples for the first approach are the carboxy terminated polyisobutylene rubbers; for the second approach are the copolymers of acrylic or methacrylic acids; and by the third approach are the sulfonated polystyrenes.
The introduction of ionizable carboxy groups is associated with either a limitation of the molecular weights of the ionomer or with a pronounced change in the characteristics of the polymer chain or both.
While the processes disclosed in the prior art in part give molecules of a desired size by ozonizing a partially unsaturated polymer, at the same time these products also contain other materials resulting from reaction of the ozone with carbon-carbon single bonds in the chain, as well as with saturated carbon atoms resulting in products having carbon chains with hydroxy, epoxy and keto groups, for instance, incorporated therein.
Although it is well recognized that long aliphatic difunctional (i.e. dihydroxy, dicarboxy or diamines, etc.) monomers have large commercial potential, products obtained by ozonolysis methods described by the prior art are deficient in several respects, as set forth above.
In addition, it is desirable to react pendant carbon-carbon double bonds in polymeric materials to produce reactive functionalities such as carboxy or hydroxyl. Such material with reactive functionalities may be utilized to produce graft copolymers and cross-linked networks.